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<FONT color="green">001</FONT>    package org.hackystat.utilities.tstamp;<a name="line.1"></a>
<FONT color="green">002</FONT>    <a name="line.2"></a>
<FONT color="green">003</FONT>    import java.util.HashSet;<a name="line.3"></a>
<FONT color="green">004</FONT>    import java.util.Set;<a name="line.4"></a>
<FONT color="green">005</FONT>    <a name="line.5"></a>
<FONT color="green">006</FONT>    /**<a name="line.6"></a>
<FONT color="green">007</FONT>     * Provides a way to guarantee unique timestamps by keeping track of the old ones and incrementing<a name="line.7"></a>
<FONT color="green">008</FONT>     * the millisecond field as needed to create a unique one. The behavior of this class is to <a name="line.8"></a>
<FONT color="green">009</FONT>     * return the passed tstamp if it is not already in the set, or else return an incremented<a name="line.9"></a>
<FONT color="green">010</FONT>     * version of the tstamp which is incremented enough times to be unique. <a name="line.10"></a>
<FONT color="green">011</FONT>     * <a name="line.11"></a>
<FONT color="green">012</FONT>     * @author Philip Johnson<a name="line.12"></a>
<FONT color="green">013</FONT>     */<a name="line.13"></a>
<FONT color="green">014</FONT>    public class TstampSet {<a name="line.14"></a>
<FONT color="green">015</FONT>      <a name="line.15"></a>
<FONT color="green">016</FONT>      /** Holds all of the tstamps previously passed to this set. */<a name="line.16"></a>
<FONT color="green">017</FONT>      private Set&lt;Long&gt; tstampSet;<a name="line.17"></a>
<FONT color="green">018</FONT>      <a name="line.18"></a>
<FONT color="green">019</FONT>      /**<a name="line.19"></a>
<FONT color="green">020</FONT>       * Create a new TstampSet, which is initialized with no knowledge of prior timestamps.<a name="line.20"></a>
<FONT color="green">021</FONT>       */<a name="line.21"></a>
<FONT color="green">022</FONT>      public TstampSet() {<a name="line.22"></a>
<FONT color="green">023</FONT>        tstampSet = new HashSet&lt;Long&gt;();<a name="line.23"></a>
<FONT color="green">024</FONT>      }<a name="line.24"></a>
<FONT color="green">025</FONT>      <a name="line.25"></a>
<FONT color="green">026</FONT>      /**<a name="line.26"></a>
<FONT color="green">027</FONT>       * Return a new unique timestamp based upon the passed timestamp.  If the passed timestamp does<a name="line.27"></a>
<FONT color="green">028</FONT>       * not exist in the timestamp set, then it is returned (and it is added to the set).  If<a name="line.28"></a>
<FONT color="green">029</FONT>       * the passed timestamp already exists in the set, then it is repeatedly incremented until a<a name="line.29"></a>
<FONT color="green">030</FONT>       * value is obtained that did not already exist in the timestamp set.  This value is then <a name="line.30"></a>
<FONT color="green">031</FONT>       * returned (and added to the set.)<a name="line.31"></a>
<FONT color="green">032</FONT>       * <a name="line.32"></a>
<FONT color="green">033</FONT>       * @param tstamp The tstamp to be used as a basis for finding a unique timestamp.<a name="line.33"></a>
<FONT color="green">034</FONT>       * @return A timestamp that did not previously exist in this TstampSet. <a name="line.34"></a>
<FONT color="green">035</FONT>       */<a name="line.35"></a>
<FONT color="green">036</FONT>      public long getUniqueTstamp(long tstamp) {<a name="line.36"></a>
<FONT color="green">037</FONT>        long currTstamp = tstamp;<a name="line.37"></a>
<FONT color="green">038</FONT>        while (tstampSet.contains(currTstamp)) {<a name="line.38"></a>
<FONT color="green">039</FONT>          currTstamp++;<a name="line.39"></a>
<FONT color="green">040</FONT>        }<a name="line.40"></a>
<FONT color="green">041</FONT>        tstampSet.add(currTstamp);<a name="line.41"></a>
<FONT color="green">042</FONT>        return currTstamp;<a name="line.42"></a>
<FONT color="green">043</FONT>      }<a name="line.43"></a>
<FONT color="green">044</FONT>    }<a name="line.44"></a>




























































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